Extreme pressure lubricant



Patented Apr. 23, 1940 EXTREME PRESSURE LUBRICANT Darwin E. Badertsche'rand Henry G. Berger, Woodbury, and Francis M. Seger, Pitman, N. J.,assigncrs to Socony-Vacuum Oil Company, Incorporated, New York, N. Y., acorporation of New York No Drawing. Application December 3, 1937, SerialNo. 177.890

9 Claims.

treme pressure lubrican which is comprised of a hydrocarbon lubricant,such as a mineral oil, containing a minor proportion of an ingredientwhich, under the extreme pressure conditions encountered, will provideor form between the engaged suriaces a lubricating film capable ofwithstanding these high pressures. Ingredients of the tim Just referredto are known as extreme pressure ingredients or extreme pressure (E. P.)bases, and numerous materials have been a proposed for such use. Amongthe various E. P. bases which have been proposed and which have met withvarying degrees of success are organic materials which contain sulfurand chlorine. Our invention is related to'this general type of compound.

It is a primary object of this invention to provide an extreme pressurelubricant which'contains a suliur-and-chlorine-containing material orcompound capable oi giving to the lubricant extreme pressure properties.'In this regard, .we

pounds obtained as products of reaction with perchloromethylmercaptan asthe reacting reagent are very effective extreme pressurelubricantaddition agents. These materials have the advantage of beingcheap and'eas'ily prepared. Perchloromethylmercaptan itself and its lowmolecular weight derivatives are very effective E. P. bases, but'wepreier to use the higher molecular weight derivatives because of theoffensive odor of the former materials.

The perchloromethylmercaptan derivatives which we have foundto beparticularly useful as E. P.'bases may be broadly divided into twogeneral classifications, namely: (1) the products obtained by reactingperchloromethylmercaptan with materials containing reactive hydrogenatoms and reactive metal atoms, and (2) the products obtained byreacting perchloromethylmercaptan with unsaturated organic materialssuch as cracked petroleum stocks, etc.

have discovered that the class or group of com- Our co-pendingapplication, Serial Number 177,891, filed December 3, 1937, is directedbroadly to perchloromethylmercaptan and its derivatives as E. P. basesand specifically to those derivatives obtained by reaction withmaterials containing reactive hydrogen or reactive metal atoms in whichthe reaction is one of substitution or so-called metathesis. 1

Our present invention is directed specifically to those materialsobtained by the reaction of perchloromethylmercaptan with organiccompounds of the unsaturated type. In' other words, our inventioncontemplates a new extreme pressure lubricant comprised of a carriersuch as hydrocarbon lubricating oil or other suitable carrying agentwhich contains as an'extreme pressure ingredient a material obtained bythe reaction of perchloromethylmercaptan with an organic materialcontaining a double bond, such for example as unsaturated fattymaterials (triolein, lard oil, cottonseed oil, linseed oil, olive oil,etc.), cracked stocks and other olefins, reformer stock, unsaturatedhalides such as allyl chloride, etc.

Although it is not our intention to limit the scope of our invention byany theory'of reaction, we believe that the reaction ofperchloromethylmercaptan with an unsaturated organic material takesplace at the double bond according to the following equation:

Inthis way it willbe seen that the substitution is made on a singlemolecule, as contrasted with certainother sulfochlorinating reactions,in which two or more molecules are united to form the reaction product.Our theory for the reaction exemplified by the above equation,therefore, would account for the fact that the products of reactioncontemplated by this invention do not tend toward insolubility in theoil as is the case with products obtained by other sulfochlorinatingreactions where the larger molecular structures are apparently formed.

Perchloromethylmercaptan, as indicated above, is a chlorinatedsubstituted sulfur chloride having the formula, ClaC-SCI, and can beprepared by the chlorination of carbon disulfide according to the methodof Helfrich and Reid (Jour. Amer. Chem. Soc. 43, 591 (1921)). Forexample, carbon disulfide containing about, 4% by weight of iodine waschlorinated in the absence of direct sunlight at a temperaturemaintained below 25 C. until the volume of the reaction mixture haddoubled. This crude product, which contained carbon tetrachloride andsulfur chlorides in addition to perchloromethylmercaptan, can be used inthe preparation of the E. P. bases contemplated by this invention, butit is preferable to purify the crude product by distillation on a Waterbath, followed by steam distillation. The material refined in this wayis practically pure.

To illustrate the manner of preparing perchloromethylmercaptanderivatives of the type contemplated by this invention, namely thereaction products of perchloromethylmercaptan with unsaturatedmaterials, the following examples are given:

(1) Reaction with 'pentene-2.40 parts by weight ofperchloromethylmercaptan and 27 parts by weight of pentene-2 were placedin a sealed container and heated to a temperature of C. over a period of23 hours. The reaction product thus formed was a dark liquid which wasdistilled to a liquid temperature of 145, C. under vacuum and thensteam-distilled to remove unreacted perchloromethylmercaptan. Theresidue from the steam-distillation was separated from the water andfiltered.

(2) Reaction with lard oil.100 parts by weight of 70-iodine number lardoil and 58 parts by weight of steam-distilled perchloromethylm'ercaptanwere mixed together and heated with stirring from a starting temperatureof 53 -C. to a final temperature of 141 C. over a period of 65 minutes.The reaction mixture was steam-distilled to remove excessperchloromethylmercaptan and the residue taken up in benzol. Alcohol wasadded to facilitate separation of emulsified water and the solvent wasdistilled 01f up to a liquid temperature of C. under vacuum. Theoil-soluble product thus obtained contained 5.60% sulfur and 16.12%chlorine.

(3) Reaction with cottonseed oil.-3l4 parts by weight of cottonseed oiland 2'? parts by weight of perchloromethylmercaptan iwere mixed togetherand heated with stirrin from an initial temperature of 31 C. to a finaltemperature of 112 C. over an interval of l-hour. The reaction productwas refined as in the preceding example.

(4) Reaction with linseed oil.50 parts by weight ofperchloromethylmercaptan and 25 parts by weight of linseed oil weremixed together and heated with stirring from an initial temperature ofabout 25 C. to a final temperature of 147 C. over an interval of 147minutes.

The linseed oil used in this experiment was rather old and probablyoxidized and polymerized.-

The final product obtained was refined according to the procedure usedin Example 2 above, and the oil-soluble refined material contained 8%sulfur and 35% chlorine.

(5) Reaction with olive oil.--A mixture of 252 parts of olive oil and140 parts of vacuum-dis-.

tilled perchloromethylmercaptan was heated with stirring from an initialtemperature of 28 C. to a final temperature of C. during 90' minutes.After refining or Working'up as in the preceding examples a fairlyviscous oil was obtained as the reaction or condensation product, suchproduct containing 19%"chlorine. and 4% sulfur.

It is to be understood that the foregoing examples are given .merely byway of illustration and that the proportions of ingredients, thereaction temperatures, the intervals of reaction, and the method ofrefinement may be varied within relatively wide limits. It is also to beunderstood that the materials with which the perchlorometrylmercaptanwas condensed are merely illustrative of unsaturated materials which maybe used to make the perchloromethylmercaptan derivatives contemplated bythis invention.

To demonstrate the effectiveness of the materials contemplated by this,invention as extreme pressure lubricant ingredients we have prepared,and tested various extreme pressure lubricant compositions comprised ofthe condensation products of perchloromethylmercaptan and theunsaturated materials described above, and hydrocarbon lubricant oil asthe carrying agent. More specifically, we have prepared variouslubricant blends from a mineral lubricating oil having a SayboltUniversal viscosity of 80-90 seconds at 210 F., to which a minorproportion of a product obtained by the reaction ofperchloromethylmercaptan with an unsaturated material has been added.The various extreme pressure lubricants prepared in this way have beensubjected to the Alme'n pin test (described by Wolf and Mougey, Free. A.P. I., 1932, pages 118-130) and the S. A. E test (described in S. A. E.Journal 39, 23-4 (1936)). These two tests are commonly accepted in theart as standards to determine the extreme pressure characteristics of alubricant.

In the table given below we show the results obtained from such tests,using the oil without the addition agent and samples of the same oilblended with the perchloromethylmercaptan derivatives of the typecontemplated by this invention.

1 At 1000 R.P.M.

From the foregoing table it will be seen that 'the products obtained bythe reaction of perchloromethylmercaptan with unsaturated organicmaterials are highly eflicient extreme pressure lubricant bases. Theamount of these materialswhich may be added to a hydrocarbon lubricantoil or other suitable carrying medium.

to form an extreme pressure lubricant composition may be varied from say.5% to 20%. It is to be understood that while We have herein describedthe derivatives or condensation products obtained with certainspecificunsaturated materials and have illustratedexemplary methods ofpreparing such derivatives, the invention is not limited to the specificcondensation products described nor the specific methods of' preparationbut includes such variations-in reactants and procedures as fairly comewithin the scope of the appended claims. that while we have referred toa hydrocarbon lubricating oil as a preferred carrying medium in theextreme pressure lubricant compositions described herein, our inventionis not limited to It is also to be understood this particular type ofcarrying agent but is inclusive generally of extreme pressure lubricantcompositions comprised of a condensation" product ofperchloromethylmercaptan and an unsaturated organic material, suchproduct being contained in any suitable carrying agent in which it maybe dissolved, dispersed or emulsified.

We claim:

1. A lubricant composition comprising a hydrocarbon lubricant oil and inadmixture therewith a minor proportion of the product obtained by thereaction of perchloromethylmercaptan with an unsaturated organicmaterial.

2. An extreme pressure lubricant comprising a hydrocarbon lubricant oiland in admixture therewith a minor proportion of the product obtained bythe reaction of perchloromethylmercaptan with an unsaturatedhydrocarbon.

3. An extreme pressure lubricant comprising a hydrocarbon lubricant oiland in admixture therewith a minor proportion of the product obtained bythe reaction of perchloromethylmercaptan with an unsaturated fatty oil.

4. An extreme pressure lubricant comprising a hydrocarbon lubricant oiland in admixture therewith a minor proportion of the product obtained bythe reaction of perchloromethylmercaptan with a material selected fromthe group consisting of lard oil, cottonseed oil, linseed .oil, oliveoil, and pentene-2.

5. An extreme pressure lubricant comprising a hydrocarbon lubricant oiland :in admixture therewith a minor proportion, from about 0.5% to about20%, of the product obtained by the reaction of perchloromethylmercaptanwith an unsaturated organic material. I

6. An extreme pressure lubricant comprising a hydrocarbon lubricant oiland in admixture therewith a minor proportion, from about 0.5% to about20%, of the product obtained by the reaction of perchloromethylmercaptanwith an unsaturated fatty oil.

7. An extreme pressure lubricant comprising a hydrocarbon lubricant oiland in admixture therewith a minor proportion, from about 0.5% to about20%, of the product obtained by the reaction of perchloromethylmercaptanwith a. material selected from the group consisting of lard oil,cottonseed oil, linseed oil, olive oil, and pentene-2.

8. The method of lubricatingmetallic bearing surfaces under abnormallyhigh pressures which comprises maintaining between said surfaces a filmof hydrocarbon lubricant which contains a minor proportion of a productobtained by the reaction of perchloromethylmercaptan with anunsaturatedorganic material.

9. An extreme pressure lubricant comprising in combination a minorproportion of the condensation product obtained by reactingperchloromethylmercaptan with an unsaturated organic material and a:major proportion of a carrying medium, such combination, when appliedto metallic bearing surfaces, forming a lubricant film capable ofwithstanding extreme pressure conditions.

